Cartridge fuse



Sept. 19, 1 933. c. HQCOLE CARTRIYDGE' FUSE Filed Jul so, 1952 Patented Sept. 19, 1933 GAR'JIREDGE Clarence H. @ole, Washington, n.

assignor to Engineering Appliance (Corporation, Baltimore, Md, a corporation of Delaware Application duly till, 1932.. Serial No, iiitdfltid 6 Claims.

This invention relates to electric fuses of the cartridge type and one object of the invention is to provide a fuse having associated therewith a visible indicator in the form of a glow lamp g which will not only serve to indicate when a fuse is burned out but by being illuminated will permit a defective fuse to be easily located at night time or in a dark cellar or cupboard Another object of the invention is to provide a fuse of the cartridge type wherein the glow lamp serving as a visible indicator is mounted within the cylindrical body]. of the fuse but set ofi from the main compartment of the body by a partition which serves to define an auxiliary l compartment and not only shields the glow lamp from flame and shock when the fuse strip is burned through but also prevents the flame from escaping through a sight opening provided for inspection of the glow lamp and creating a fire hazard.

Another object of the invention is to provide a fuse of the cartridge type having a visible indi cator associated therewith and so mounted that when the fuse strip is burned through it maybe removed and a new one applied without disturbing the indicator.

Another object of the invention is to provide a fuse of this character which is extremely simple in construction, efficient in operation and cheap to manufacture. The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a longitudinal sectional view through one embodiment of the improved fuse;

Figure 2 is a sectional view taken longitudinally through a fuse of a modified construction;

Figure 3 is, a transverse sectional view taken along the line 33 of Figure 2;

Figure 4 is a perspective view of the partition forming strip shown in Figure 1; and

Figure 5 is a perspective view of the partition forming strip shown in Figure 2.

This improved fuse has a cylindrical body 1 formed of insulation which may be fiber, hard rubber, porcelain, or any other suitable material. The body may be of any length and diameter desired and intermediate its length is formed with a side opening 2 constituting a sight open opening through which a visible indicator may be inspected in order to determine whether or not 50 the fuse has been burned out. Terminals 3 are applied to ends of the cylindrical body and each consists of a metal sleeve 4 having an internal circumferentially extending flange 5 and is internally threaded between this flange and both 55 ends of the sleeve. Therefore, the sleeve may be screwed upon the body with its flange 5 hear-- ing against an end of the body and when in place, the sleeve will project from the body longitudinally thereof. A strip 6 of fusible material extends longitudinally through the body and has its ends passed through slots 7 formed in metal disks 8 fitted into the sleeve i and after extended ends of the fuse strip have been bent to form anchors 9 which extend across outer faces of the disks 8 caps or heads 10 of metal are screwed into outer end portions of the sleeve and the anchors 9 will be firmly gripped between the disks 8 and caps 1d and the fuse strip firmly held in place and prevented from sliding longitudinally or moving transversely out of its proper position.

The visible indicator which is to be observed through the sight opening 2 in order to determine whether or not the fuse strip has been burned through consists of a glow lamp ll containing a low potential mixture of inert gases and commonly known as a neon tube. Conductors 12 extend from the bulb or lamp l1 longitudinally of the cylindrical body and have their ends ex tending beyond the body and bent as shown at 13 to bear against ends of the body where they will be engaged by the flanges 5 of the terminals 3 and firmly gripped to reestablish electrical communication between the glow lamp and the terminals. It will thus be seen that when the fuse strip 6 is burned through, current may pass through the glow lamp by way of the conductors 12 and the glow lamp will be illuminated and positively indicate that the fuse strip of this particular fuse has been burned through.

In order to isolate the glow lamp from the main chamber of the body in which the fuse strip 6 is located, there has been provided a partition 14 formed from a strip of yieldable insulation. The strip or partition extends longitudinally in the body and has an enlarged cup-shaped intermediate portion 15 from which extends reduced end portions or tongues 16. The cupshaped intermediate portion of the partition strip encloses the glow lamp 11 and resistance 17 associated therewith thereby defining an auxiliary compartment. The tongues-lfi extend from the intermediate portion "15 in flat contacting engagement with walls of the body where they are secured by rivets 18 covered at their outer ends by the sleeves 4 of the terminals and in each tongue is formed a longitudinally extending groove 19 to receive the conductors l2 and prevent the conductors from moving out of their proper position. Ends of the tongues extend in overlapping engagement with the flanges 5 in order to prevent end portions of the conductors from being exposed and damaged by flaming gases created when the fuse strip 6 burns through.

5 The cup-shaped intermediate portion of the partition strip not only defines an auxiliary chamber to receive the glow lamp and its resistance but also serves to shield the glow lamp and resistance from flaming gases when the fuse strip -burns through and acts as a shock absorber to prevent the lamp from being broken by the force of an explosion. Movement of the yieldable wall under force of an explosion will serve to expel air from the auxiliary chamber through the sight opening and, therefore, after the 'ex plosion, such gases which escape into the auxiliary compartment may easily pass through the compartment and out through thesight open- When this fuse is in use it is set in place in the usual manner with its terminals 3 engaged with the resilient clips of a mounting andordinarily current will pass from one terminal to the other by way of the fuse strip. When the fuse strip is burned through current will then pass through the glow lamp by way of the conductors and associated resistance and the glow lamp will be illuminated. This will indicate which fuse of a number in a fuse box has been burned out and in' addition illuminate the fuse so that it may be easily seen and removed. The cap 10 and disks 8 can then be removed in order to insert a new fuse strip after which the fuse will be again assembled and can be replaced in the fuse box. It should also be noted that if it is found that the fuse. continues to blow, a fuse strip of greater capacity may be inserted thereby making it unnecessary to discard the entire fuse.

The form of fuse illustrated in Figures 2, 3 and 5 is quite similar to that shown in Figure 1 and has a cylindrical body 15 of insulating material formed intermediate its length with a sight opening 16. The terminals 17 are carried by end portions of the body and eachconsists of a metal sleeve 18' screwed upon the body and formed with an internal annular flange 19' similar to the flange 5 except that about the margin of each flange 19 there has been formed an inwardly extending annular lip 20. A renewable fuse strip 21 extends longitudinally through the body and has its ends passed outwardly through slots 22 formed in disks 23 corresponding to the disks 8 and bent end portions 24 of the fuse strip are engaged by caps 25 corresponding to the caps 10 and screwed into end portions of the sleeve 18.

In order to define the auxiliary compartment 26 in which is located the glow lamp 27 and associated resistance 28 there has been provided a partition 29 consisting of a strip of yieldable insulation. This partition forming strip is curved longitudinally throughout its length as shown clearly in Figures2 and 5 and it tapers towards both ends. Therefore, edge portions of the partition strip would'bear against walls of the body and end portions of the strip may bear against inclined surfaces 30 formed at opposite ends of the body where they will be held due to the fact that the marginal lips 20 of the flanges 19 overlap ends of the partition strip. The partition strip will therefore be firmly held in place and prevented from moving longitudinally or transversely out of its proper position.

Referring to Figure 2 it will be seen that the conductors 31 extend longitudinally in the auxiliary compartment towards ends thereof and have their end portions gripped between ends of the partition strip and inclined surfaces 30 of the body, extreme ends of the conductors being bent flat against end edges of the body and engaged by the flanges 5 of the terminals. Therefore,- when the fuse strip is burned out current may pass through the glow lamp by way of the conductors and the glow lamp will be illuminated.

Manifestly, the construction herein shown is capable of considerable modifications and such modifications as come within the scope of my claims, I consider within the spirit of my invention.

I claim:-

1. A fuse comprising a cylindrical casing of insulation formed with a sight opening, terminals closing ends of the casing, a removable partition extending longitudinally in said casing and dividing the casing into a main compartment and an auxiliary compartment, a fuse strip extending longitudinally in the main compartment and having its ends attached to the terminals, the sight opening communicating with the auxiliary compartment, and a glow lamp in the auxiliary compartment having conductors extending out of the auxiliary compartment and engaged by said terminals.

2. A fuse comprising a cylindrical casing of insulation formed with a sight opening, terminalsclosing ends of the casing, a detachable partition extending longitudinally in said casing and dividing the casing into a main compartment and an auxiliary compartment, a fuse strip extending longitudinally in the main compartment and having its ends attached to the terminals, the sight opening communicating with the auxiliary compartment, said partition consisting of a strip of insulation having its end portions contacting with the body and its intermediate portion spaced from the same to define the auxiliary compartment, and a glow lamp in the auxiliary compartment and having conductors extending longitudinally therein and outwardly between the ends of the strip and walls of the body and engaging the terminals.

3. A fuse comprising a cylindrical casing of insulation formed with a sight opening, terminals closing ends of the casing, a partition extending longitudinally in said casing and dividing the casing into a main compartment and an auxiliary compartment, a fuse strip extending longitudinally in the main compartment and having its ends attached to the terminals, the sight opening communicating with the auxiliary compartment, said partition consisting of a strip of insulation having a cup shaped intermediate iliary compartment, a fuse strip extending longitudinally in the main compartment and having its ends attached to the terminals,-the sight opening communicating with the auxiliary compartment, said partition consisting of a strip of insulation having a cup-shaped intermediate portion aaa'asse defining the auxiliary compartment and reduced end portions fitting against walls of the body and at their ends contacting with said terminals, the reduced end portions of the strip being formed with longitudinally extending grooves, and a glow lamp in the auxiliary compartment having con eluctors extending from ends of the compartment through'said grooves and contacting with the ter K113123815,

E. A fuse comprising a cylindrical casing of in= sulation formed with a sight opening, terminais closing ends of the casing, a partition extending longitudinally in said casing and dividing the easing into a main compartment and an auxiliary compartment, a fuse strip extending longitudinaily in the main compartment and having its ends attached to the terminals, the sight opening communicating with the auxiliary compartment, said partition consisting of a strip of insulation bowed longitudinally and tapered towards its ends and having edges contacting with walls of the body and its ends bearing against said termi nals, and a glow lamp in the auxiliary compart== ment having conductors extending towards ends of the compartment and contacting with the ter 6. A fuse comprising a cylindrical casing of in-= sulation formed with a sight opening, terminals closing ends of the casing, a partition extending longitudinally in said casing and dividing the easing into a main compartment and an auxiliary compartment, a fuse strip extending iongitudinally in the main compartment and having its ends attached to the terminals, the sight opening communicating with the auxiliary compartment, said partition consisting of a strip of insulation loowed longitudinally and tapered towards its ends and having edges contacting with walls of the body, said terminals each fitting about an end portion of the body and formed with an integral annular flange having 9. marginal lip extending into the body and overlap ping an end of said strip to secure the strip in place, and a glow lamp in said auxiliary compartment having conductors extending towards ends of the compartment and between ends of the strip and walls of the body and contacting with flanges of the terminals.

@LARENCE H. COLE. 

